Aryl alkylphosphonothioates



nite tates 3,085,044 Patented Apr. 9, 1963 3,085,044 ARYL ALKYLPHOSPHONOTHIOATES John P. Chupp, Kirkwood, and Peter E. Newallis, Crestwood, Mo., assignors to Monsanto Chemical Company, St. Louis, Mo., a corporation of Delaware No Drawing. Filed Apr. 4, 1961, Ser. No. 100,502 20 Claims. (Cl. 167-30) wherein n is an integer from to 1, wherein R is a lower alkyl radical (e.g. methyl, ethyl, propyl, butyl, amyl, and the various isomeric forms thereof containing up to 5 carbon atoms) and wherein R is an aromatic hydrocarbon radical of the benzene series containing 6 to 10 carbon atoms (e.g. phenyl, tolyl, xylyl, ethylphenyl, cumyl, tert-butylphenyl, and the various isomeric forms thereof). In general It will be zero, R will :be methyl or ethyl but usually methyl, and R will be phenyl or tolyl but usually phenyl.

The preferred method of this invention comprises reacting a nitrophenol of the formula EEO-Q H2) DH wherein n has the aforedescribed significance with an alkylphosphonohalidothionate of the formula wherein R and R have the aforedescribed significance and wherein Z is a halogen of atomic number in the range of 16 to 36 (i.e. chlorine or bromine, usually chlorine) in the presence of hydrogen halide scavenging agent (e.g. sodium carbonate, potassium carbonate, the tertiary organic amines such as triethylamine, tri-n-propylamine, tri-n-butylamine, dimethylaniline, lutidine, l-pipecoline, pyridine, etc.) in an amount at least sufiicient to absorb the hydrogen halide by-product. The scavenging agent can be added at the beginning of the reaction or throughout the course of the reaction. While a wide range of reaction temperatures can be employed provided the system is fluid (i.e. a reaction temperature above the freezing point of the system up to and including the boiling point of the system) it is preferred to employ a reaction temperature in the range of about 20 C. to about 120 C. Where and when desired an inert organic solvent (e.g. benzene, xylene, toluene, acetone, butanone, dioxane, etc.) can be used. Ordinarily the respective react-ants will be employed in substantially equimolecular proportions.

As illustrative of nitrophenol reactants of the preferred process of this invention are Z-nitrophenol, S-nitrophenol,

2. 4-nitrophenol, 2-nitro-4-methylphenol, 2-nitro-3-methylphenol, 3-nitro-4-methylphenol, 2-methyl-4-nitrophenol, -3-methyl-4-nitrophenol, etc. As illustrative of alkylphosphonohalidothionate reactants of the preferred process of this invention are O-phenyl methylphosphonochloridothionate,

O-phenyl ethylphosphonochloridothionate,

O-phenyl n-propylphosphonochloridothionate,

O-phenyl isoamylphosphonobromidothionate,

O-(p-tolyl) methylphosphonochloridothionate,

O- (m-tolyl) methylphosphonochloridothionate,

O-(o-tolyl) ethylphosphonochloridothionate,

O-(p-cumyl) methylphosphonobromidothionate,

O (p-t-butylphenyl) methylphosphonochlorido-thionate,

etc.

As illustrative of the preferred method of this invention but not limitative thereof is the following:

Example 1 To a suitable reaction vessel equipped with a thermometer, agitator and reflux condenser is charged approximately 1'32 par-ts by Weight of benzene, approximately? .0 parts by weight (substantially 0.05 mole) of 4-nitrophenol, approximately 6.1 parts 'by weight (substantially 0.06 mole) of triethylamine, and approximately 10.4 parts by weight (substantially 0.05 mole) of O -phenylmethylphosphonochloridothionate. While agitating the mixture is heated up to the reflux temperature and then refluxed for 5 hours. The reaction mass is then cooled to room temperature and then quenched with water. The organic layer is separated and washed first with aqueous 3% sodium carbonate and then with water. The sowashed solution is then stripped of volatiles under vacuurn. The residue, a white solid melting at 78.5-80 C., is O-phenyl O-(4-nitrophenyl) methylphosphonothioate;

Analysis.'l'heory: 10.0% P, 10.3% S. Found: 9.9% P, 10.3% S.

Example 11 Employing the procedure of Example I but replacing 4nitrophenol with an equimolecular amount of 2-nitrophenol there is obtained O-phenyl O4(2-nitropheny1) methylphosphonothioa-te which is insoluble in water;

ExampleI II To a suitable reaction vessel equipped with a thermometer, agitator and reflux condenser is charged approximately 176 parts by weight of benzene, approximately 7.0 parts by weight (substantially 0.05 mole) of 4-nitrophenol, approximately 6.1 parts by weight substantially 0.06 mole) of triethylamine, and approximately 11.0 parts by weight (substantially 0.05 mole) of O-(o-tolyl) methylphosphonochloridothionate. While agitating the mixture is heated up to the reflux temperature and then refluxed for 5 hours. The reaction mass is -then' cooled to room temperature and then quenchediwith water. The organic layer is separated and washed first with aqueous- 3% sodium carbonate and then with water. The so- Washed solution is then stripped of volatiles under vacuum. The residue, a white solid (recrystallizing from ethyl alcohol gave an M.P. of 7 l-7.l.5 Q), is O (otolyl) O'- (4-nitropheny1) methylphosphonothioate. V

Analysis.Theory: 9.6% P, 9.9% S. Found: 9.4% P, 9.7% S. a 3

Example IV Employing the procedure of Example III but replacing O-(o-tolyl) -methylphosphonochloridothionate with an equimolecular amount of O-(o-tolyl) ethylphosphonobromidothionate there is obtained O-(O-tolyl) O-(4-nitrophenyl)ethylphosphonothioate which is insoluble in water.

Example V ing the mixture is heated up to the reflux temperature and then refluxed for hours. The reaction mass is then cooled to room temperature and then quenched with water. The organic layer is separated and washed first with aqueous 3% sodium carbonate and then with water. The so-washed solution is then stripped of volatiles under vacuum. The residue, a brown oil which solidilied on standing (M.P. 57-59 C.), is O-(m-tolyl) O-(4- nitrophenyl) methylphosphonothioate.

Analysis.-Theory: 9.6% P, 9.9% S, 4.3% N. Found: 9.3% P, 9.8% S, 4.2% N.

Example VI Employing the procedure of Example V but replacing 4-nitrophenol with an equimolecular amount of 3-methyl- 4-nitrophenol there is obtained O-(m-tolyl) O-(3-methyl- 4-nitrophenyl) methylphosphonothioate which is insoluble in water.

Example VII To a suitable reaction vessel equipped with a thermometer, agitator and reflux condenser is charged approximately 176 parts by Weight of benzene, approximately 7.0 parts by weight (substantially 0.05 mole) of 4-nitrophenol, approximately 6.1 parts by weight (substantially 0.06 mole) of triethylamine, and approximately 10.4 parts by weight (substantially 0.05 mole) of O-(ptolyl) methylphosphonochloridothionate. While agitating the mixture is heated up tothe reflux temperature and then refluxed for 6 hours. The reaction mass is then cooled to room temperature and then quenched with water. The organic layer is separated and washed first with aqueous 3% sodium. carbonate and then with water. The so-washed solution is then stripped of volatiles under vacuum. The residue, alight brown solid (recrystallizing from cyclohexane gave a MP. of 107-108 C.), is O-(p-tolyl) O-(4-nitrophenyl) methylphosphono thioateg f Analysis-Theory: 9.6% P, 9.9% S. Found: 9.5% P, 9.2% S.

Example VIII Employing the procedure of Example VII but replacing O-(p-tolyl) methylphosphonochloridothionate with an equimolecular amount of O-(m-tert.-butylphenyl) isoamylphosphonobromidothionate there is obtained O-(mtert.-butylphenyl) O-(4-nit-rophenyl) isoamylphosphonothioate.

Example IX To a suitable reaction vessel equipped with a thermometer, agitator and reflux condenser is charged approximately 176 parts by weight of benzene, approxirnately 7.0 parts by weight (substantially 0.05 mole) of 4-nitrophenol, approximately 6.1 parts by weight (substantially 0.06 mole) of triethylamine, and approximately 11.5 parts by weight (substantially 0.05 mole) of O- phenyl ethylphosphonochloridothionate. While agitating the mixture is heated up to the reflux temperature and then refluxed for 6.5 hours. The reaction mass is then cooled to room temperature and then quenched with water. The organic layer is separated and washed first with aqueous 3% sodium carbonate and then with water. The so-washed solution is then stripped of volatlies under vacuum. The residue, a white solid (recrystallizing from hexane gave a M.P. of 51.5-52.5 (3.), is O-phenyl O- (4-nitrophenyl) ethylphosphonothioate.

Analysis.Theory: 9.6% P, 9.9% S. Found: 9.5% P, 9.5 S.

Example X Employing the procedure of Example IX but replacing 4-nitrophenol with an equimolecular amount of 2- nit-r-ophenol there is obtained O-phenyl O-(Z-nitrophenyl) ethylphosphonothioate which is insoluble in water.

As illustrative of the alternative method of this invention but not limitative thereof is the following:

Example X] To a suitable reaction vessel equipped with a thermometer, agitator. and reflux condenser is charged approximately 220 parts by weight of benzene, approx-irnately 6.1 parts by weight of o-ethylphenol, approximately 5.1 parts by weight of triethylamine, and approximately12.6 parts by weight of O-(4,nitrophenyl) methylphosphonochloridothionate. While agitating the mixture is heated up to the reflux temperature and then refluxed for 4 hours. The reaction mass is then cooled to room temperature and then quenched with water. The organic layer is separated and washed first with aqueous 3% sodium carbonate and then with water. The so-washed solution is then stripped of volatiles under vacuum. The residue, a solid (recrystallizing from hexane gave a M.P. of 64-66 (3.), is O-(o-ethylpheny-l) O-(4-nitrophenyl) methylphosphonothioate.

Example XII Employing the procedure of Example XI but replacing o-ethylphenol with an equimolecular amount of omethylphenol (i.e. o-cresol) there is obtained O-(oniethylphenyl) 'O-(4-nitrophenyl) methylphosphonothioate which is insoluble in water.

The methods by which the alkylphosphonothioates of this invention are isolated will vary slightly with the reactants employed and the product produced. Further purification by selective solvent extraction or by absorptive agents such as activated carbon or clays can precede the removal of the inert organic liquid or solvent when such is employed. Additionally an inert organic solvent can be added to and in the purification by absorptive agents. However, the product is generally satisfactory for insecticidal purposes without further purification.

As illustrative of other alkylphosphonothioates of this invention are ticularly useful group are the O-(4-nitrophenyl) alkylphosphonothioates of the formula f wherein R is an alkyl radical containing 1 to 2 carbon atoms, and wherein R is phenyl, m-tolyl or o-tolyl.

It will be understood that the terms insect and insecticide are used herein in their broad common usage to include spiders, mites, ticks, and like pests which are not in the strict biological sense classed as insects. Thus the usage herein conforms to the definitions provided by Congress in Public Law 104, the Federal Insecticide, Fungicide, and Rodenticide Act of 1947, Section 2, subsection h, wherein the term insec is used to refer not only to those small invertebrate animals belonging mostly to the class Insecta, comprising six-legged, usually winged forms, as beetles, bugs, bees, flies, and so forth, but also to other allied classes of arthropods whose members are Wingless and usually have more than six legs, as spiders, mites, ticks, centipedes, and wood lice.

The alkylphosphonothioates of this invention are effective against a wide variety of insects and as illustrative of their activity but not limitative thereof is the following:

A rimless, 25 x 200 mm. culture tube is rinsed with acetone and is placed in a holding block. The tube is filled with 50 cc. of distilled water. Next 0.1 cc. or 0.1 gram of the compound to be evaluated is dissolved in acetone to make a 1% by weight concentrate of the compound. 0.05 ml. of this concentrate is pipetted into the culture tube containing the distilled water. The tube is then stoppered with an acetone Washed rubber stopper and shaken vigorously to facilitate complete mixing. Approximately 25 early fourth instar yellow fever mosquito larvae (Adesaegypti) are transferred to the tube with the aid of a pipette. The larvae are held in the test tube at room temperature for 24 hours at which time mortality observations are taken. This procedure is repeated at decreasing concentrations until a 100% kill is observed. Employing the below itemized compounds 100% kills Were observed atthe indicated concentrations in parts per million:

P.p.m.

O-phenyl O-(4-nitrophenyl) methylphosphonothioate 0.04 O-meth-yl O-(4-nitrophenyl) phenylphosphonothioate 1.00 O-phenyl v O-(4-nitrophenyl) ethylphosphonothioate 0.04 O-(o-tolyl) O-(4-nitrophenyl) methylphosphonothioate- 0.04 O-(m-tolyl) O-(4-nitrophenyl) methylphosphonothioate 0.04 O-(p-tolyl) O-(4-ni-trophenyl) A 1% by weight concentrate is prepared by dissolving the compound to be evaluated in ml. of acetone. A 0.25 cc. tuberculin, B-D Yale syringe is filled with this concentrate and placed in a microinjection apparatus. The injector lever is pressed several times to make certain no air bubbles are trapped in the needle and the needle is wiped with filter paper to remove any excess solution. The injector lever is pressed once to deliver one microliter which is applied directly to each of 12 lima bean leaf discs 0.25 inch in diameter. Individual second instar southern armyworm lanvae (Prodenitz eridania) are placed on each disc and the disc encaged with a plastic cap. After 48 hours at room temperature mortality observations are made. This procedure is repeated at decreasing concentrations and until a 100% methylphosphonothioate- 0.40

kill is observed. Employing the below itemized compounds 100% kills were observed at the indicated'concentrations in micrograms per larva:

6 O-(o-tolyl) O-(4-nitrophenyl) methylphosphonothioate 0.20 O-(m-tolyl) O-(4-nitrophenyl) methylphosphonothioate 0.20 O-(p-tolyl) O-(4-nitrophenyl) methylphosphonothioate 2.00

A 1% by weight concentrate of the compound to be evaluated is prepared by dissolving the chemical in 10 ml. of acetone. A 0.25 cc. tuberculin, B-D Yale syringe is filled with the concentrate and placed in a microinjection apparatus. The injector lever is pressed several times to make certain that no air bubbles are trapped in the needle and the needle is wiped with filter paper to remove any excess solution. The injector lever is pressed once to produce one rnicroliter which is applied directly to the ventral side of the abdomen of each of 10 plum curculio (Conolrachelus nenuphar). After application each insect is released within observation dishes and held for 24 hours at room temperature and mortality observations made at the end of that time. This procedure is repeated at decreasing concentrations until a kill is observed. Employing the below itemized compounds 100% kills were observed at the indicated concentrations in micrograms per insect:

O-phenyl .O-(4-nitrophenyl) methylphosphonothioate 0.2 O-methyl O-(4-nitrophenyl) phenylphosphonothioate 10.0 O-phenyl O-(4-nitrophenyl) ethylphosphonothioate 0.2 O-(o-tolyl) O(4-nitrophenyl) methylphosphonothioate--- 0.2 O-(m-tolyl) 'O-(4-nitrophenyl) methylphosphonothioate- 2.0

Although the phosphonothioates of this invention are useful per se in controlling a wide variety of insect pests, it is preferable that they be supplied to the pests or to the environment of the pest or pests in a dispersed form in a suitable extending agent.

In the instant specification and appended claims it is to be understood that the term dispersed is used in its widest possible sense. When it is said that the phosphonothioates of this invention are dispersed, it means that particles of the phosphonothioates of this invention may be molecular in size and held in true solution in a suitable organic solvent. It means further, that the particles may be colloidal in size and distributed throughout a liquid phase. in the form of suspensions or emulsions or in the form of particles held in suspension by wetting agents. It also includes particles which are distributed in a semi-solid viscous carrier such as petrolatum or soap or other ointment base in which they may be actually dissolved in the semi-solid or held in suspension in the semi-solid with the aid of suitable wetting or emulsifying agents. The term dispersed" also means that the particles may be mixed with and distributed throughout a solid carrier providinga mixture in particulate form, e.g. pellets, granules, powders, or dusts. The term dispersed also includes mixtures which are suitable for use as aerosols including solutions, suspensions, or emulsions ofthe phosphonothioates of this invention in a carrier such as dichlorodiiiuoromethane and the like fluorochloroal-kanes which boil below room temperature at atmospheric pressure. a

In the instant specification and appended claims it is to be understood that the expression extending agent includes any and all of those substances in which the phosphonothioates of this invention are dispersed. It includes, therefore, the solvents of a true solution, the liquid phase of suspensions, emulsions or aerosols, the semisolid carrier of ointments and the solid phase of particulate solids, e.g. pellets, granules, dusts and powders.

The exact concentration of the phosphonothioates of this invention employed in combatting or controlling insect pests can vary considerably provided the required dosage (i.e. toxic or lethal amount) thereof is supplied to the pests or to the environment of the pests. When the extending agent is a liquid or mixture of liquids (e.g. as in solutions, suspensions, emulsions, or aerosols) the concentration of the phosphonothioate employed to supply the desired dosage generally will be in the range of 0.001 to 50 percent by weight. When the extending agent is a semi-solid or solid, the concentration of the phosphonothioate employed to supply the desired dosage generally will be in the range of 0.1 to 25 percent by weight. From a practical point of view, the manufacturer must supply the agriculturist with a low-cost concentrate or spray base or particulate solid base in such form that, by merely mixing with water or solid extender (e.g. powdered clay or talc) or other low-cost material available to the agriculturist at the point of use, he will have an easily prepared insecticidal spray or particulate solid. In such a concentrate composition, the phosphonothioate generally will be present in a concentration of to 95 percent by weight, the residue being any one or more of the well known insecticidal adjuvants, such as the various surface active agents (e.g. detergents, a soap or other emulsifying or wetting agent), surface-active clays, solvents, diluents, carrier media, adhesives, spreading agents, humec-tants, and the like.

There are a large number of organic liquids which can be used for the preparation of solutions, suspensions or emulsions of the phosphonothioates of this invention. For example, isopropyl ether, acetone, methyl ethyl ketone, dioxane, cyclohexanone, carbon tetrachloride, ethylene dichloride, tetrachloroethane, hexane, heptane and like higher liquid alkanes, hydrogenated naphthalenes, solvent naphtha, benzene, toluene, xylene, petroleum fractions (e.g. those boiling almost entirely under 400 'F. at atmospheric pressure and having a flash point above about 80 F., particularly kerosene), mineral oils having an unsulfonatable residue above about 80 percent and preferably above about 90 percent. In those instances wherein there may be concern about the phytotoxicity of the organic liquid extend-ing agent a portion of same can be replaced by such low molecular Weight aliphatic hydrocarbons as dipentene, diisobutylene, propylene trimer, and the like or suitable polar organic liquids such as the aliphatic ethers and the aliphatic ketones containing not more than about carbon atoms as exemplified by acetone, methyl ethyl ketone, diisobutyl ketone, dioxane, isopropyl ether, and the like. In certain instances, it is advantageous to employ a mixture of organic liquids as the extendingagent.

When the phosphonothioates of this invention are to be supplied to the insect pests or to the environment of the pests as aerosols, it is convenient to dissolve them in a suitable solvent and disperse the resulting solution in dichlorodifluoromethane or like chlorofluoroalkane which boils below room temperature at atmospheric pressure.

The phosphonothioates of this invention are preferably supplied to the insect pests or to the environment of the insect pests in .the form of emulsions .or suspensions.

.Emulsions or suspensions are prepared by dispersing the phosphonothioate of this invention either per se or in the form of an organic solution thereof in water with the aid of a water-soluble surfactant. The term surfactant as employed here and in the appended claims is used as in volume 11 of Schwartz, Perry and Berchs Surface Active Agents and Detergents (1958, 'Interscience Publishers,

Inc., New York) in place of the expression emulsifying agent to connote generically the various emulsifying agents, dispersing agents, wetting agents and spreading agents that are adapted to be admixed with the active compounds of this invention in order to secure better wetting and spreading of the active ingredients in the water vehicle or carrier in which they are insoluble through lowering the surface tension of the water (see also Erear, Chemistry of Insecticides, Fungicides and Herbicides, second edition, page 280). These surfactants include the well-known capillary-active substances which may be an anion-active (or anionic), cation active (or cationic), or non-ionizing (or non-ionic) which are described in detail in volumes I and II of Schwartz, Perry and Berchs Surface Active Agents and Detergents (195 8, Interscience Publishers, Inc., New York) and also in the November 1947 issue of Chemical Industries (pages 811824) in an article entitled Synthetic Detergents by John W. McCutcheon, and also in the July, August, September and October 1952 issues of Soap and Sanitary Chemicals under the title Synthetic Detergents. The disclosures of these articles with respect to surfactan-ts, i.e. the anion-active, cation-active and the nonionizing capillary active substances, are incorporated in this specification by reference in order to avoid unnecessary enlargement of this specification. The preferred surfactants are the water-soluble anionic surface-active agents and the water soluble non-ionic surface-active agents set forth in U.S. 2,846,398 (issued August 5, 195 8). -In general it is preferred that a mixture of watersoluble anionic and water-soluble non-ionic surfactants be employed. 7

The phosphonothioa-tes of this invention can be dispersed by suitable methods (e.g. tumbling or grinding) in solid extending agents either of organic or inorganic nature and supplied to the insect pests environment in particulate form. Such solid materials include for example, tricalcium phosphate, calcium carbonate, kaolin, bole, kieselguhr, talc, bentonite, fullers earth, pyrophyllite diatomaceous earth, calcined magnesia, volcanic ash, sulfur and the like inorganic solid materials, and include, for example, such materials of organic nature as powdered cork, powdered wood, and powdered walnut shells. The preferred solid carriers are the adsorbent clays, e.g. bentonite. These mixtures can be used for insecticidal purposes in the dry form, or by addition of watersoluble surfactants or Wetting agents the dry particulate solids can be rendered wettable by Water so as to obtain stable aqueous dispersions or suspensions suitable for use as sprays.

For special purposes the phosphonothioates of this invention can be dispersed in a semi-solid extending agent such as petroleum or soap (e.g. sodium stearate or oleate or palmitate or mixtures thereof) with or without the 31d of solubility promoters and/or surfactants or dispersmg agents.

In all of the forms described above the dispersions can be provided ready for use in combatting insect pests or they can be provided in a concentrated form suitable for mixing with or dispersing in other extending agents. As illustrative of a particularly useful concentrate is an intimate mixture of phosphonothioate of this invention with a water-soluble surfactant which lowers the surface tension of Water in the Weight proportions of 0.1 to 15 parts of surfactant with sufficient of the phosphonothioate of this invention to make 100 parts by weight. Such a concentrate is particularly adapted to be made into a spray for combatting various forms of insect pests by the addition of water thereto. As illustrative of such a concentrate is an intimate mixture of parts by weight of O-phenyl O-(4-nitr0phenyl) methylphosphonothioate and 5 parts by weight of a water-soluble non-ionic surfactant such as the polyoxyethylene derivative of sorbitan monolaurate.

Another useful concentrate adapted to be made into a spray for combatting a variety of insect pests in a solution (preferably as concentrated as possible) of a phos phonothioate of this invention in an organic solvent therefor. The said liquid concentrate preferably contains dissolved therein a minor amount (e.g. 0.5 to 10 percent by weight of the Weight of the new insecticidal agent) of a surfactant (or emulsifying agent), which surfactant is also water-soluble. As illustrative of such a concentrate 9 V is a solution of O-(m-tolyl) O-(4-nitrophenyl) methylphosphonothioate in benzene which solution contains dissolved therein a water-soluble polyoxyethylene glycol nonionic surfactant and a Water-soluble alkylary sulfonate anionic surfactant.

Of the surfactants aforementioned in preparing the various emulsifiable, wettable or dispersible compositions or concentrates of this invention, the anionic and nonionic surfactants are preferred. Of the anionic surfactants, the particularly preferred are the well known watersoluble alkali metal alkylaryl sulfonates as exemplified by sodium decylbenzene sulfonate and sodium dodecylbenzene sulfonate. Of the non-ionic surfactants, the particularly preferred are the water-soluble polyoxyethylene derivative of alkylphenols (particularly isooctyphenol) and the water-soluble polyoxyethylene derivatives of the monohigher fatty acid esters of hexitol anhydrides (e.g. sorbitan). These materials in general contain 15 to 30 moles of ethylene oxide per mole of the hexitol anhydride or the alkylphenol.

In all of the various dispersions described hereinbefore for insecticidal purposes, the active ingredient can be one or more of the compounds of this invention. The compounds of this invention can. also be advantageously employed in combination with other pesticides, including for example, nematocides, bactericides, and herbicides. In this manner it is possible .to obtain mixtures which are effective against a wide variety of pests and other forms of noxious life.

In controlling or combatting insect pests the phosphonothioates of this invention either per se or compositions comprising same are supplied to the insect pests or to their environment in a lethal or toxic amount. This can be done by dispersing the new insecticidal agent or insecticidal composition comprising same in, on or over an infested environment or in, on or over an environment the insect pests frequent, e.g. agricultural soil or other growth media or other media infested with insect pests or attractable to the pests for habitational or sustenance or propagational purposes, in any conventional fashion which permits contact between the insect pests and the phosphonothioates of this invention. Such dispersing can be brought about by applying sprays or particulate solid compositions to a surface infested with the insect pests or attractable to the pests, as for example, the surface of an agricultural soil or other media such as the above ground surface of plants by any of the convention methods, e.=g. power clusters, boom and hand Sprayers, and spray dusters. Also for sub-surface application such dispersing can be carried out by simply mixing the new insecticidal agent per Se or insecticidal spray or particulate solid compositions comprising same with the infested environment or with the environment the insect pests frequent, or by employing a liquid carrier for the new insecticidal agent to accomplish sub-surface penetration and impregnation therein.

An alternative method of this invention comprises reacting a monohydroxy substituted aromatic hydrocarbon or mixtures thereof of the formula R'OH wherein R has the aforedescribed significance (e.g. phenol, the various cresols, such as o-cresol, m-cresol, p-cresol, commercial mixtures of cresols per se or in admixture with phenolyand. or the Xylenols, the various xylenols, the various ethylphenols, carvacrol, tert.-butylphenol, and the various isometric forms thereof containing 6 to 10 carbon atoms) with an alkylphosphonohalidothionate of the formula N02 SI wherein R, Z and n have the aforedescribed significance i0 0-.(4-nitrophenyl) methylphosphonochloridothionate O-(4-nitrophenyl) ethylphosphonobromidothionate O -(2-nitrophenyl) ethylphosphonochloridothionate 0-(2-nitrophenyl) methylphosphonochloridothionate 0-(3-methyl4-nitrophenyl) methylphosphonochloridothionate O-(4-nitrophenyl) isoamylphosphonobromidothionate etc. 1 in the presence of a hydrogen halide scavenging agent such as the aforedescribed. Where and when desired an inert organic solvent such as benzene, toluene, Xylene, acetone, butanone, dioxane, etc., can be used. While a wide range of reaction temperatures can be employed provided the system is fluid (i.e. above the freezing point of the system up to and including the systems boiling point) it is preferred to employ a reaction temperature in the range of about 20 C. to about C. Ordinarily the respective reactants will be employed in substantially equimolecular proportions.

Example XIII Employing the procedure of Example XI but replacing o-ethylphenol with a substantially equimolecular amount of a commercial mixture of cresols having m:p:o weight ratio of approximately 5.4:2.9: 1.0 there is obtained a mixture of O-(cresyl) O-(4-nitrophenyl) methylphosphonothioates having the same weight ratio of mzpzo isomers. This material is insoluble in water.

Generically the processes of this invention comprise reacting a hydroxy substituted aromatic compound of the formula A--OH with an alkylphosphonohalidothionate of the formula wherein R and Z have the aforedescribed significance and wherein A and B are unlike radicals of the group R and out) all wherein n is an integer from 0 to 1, wherein R is a lower alkyl radical, and wherein R is an aromatic hydrocarbon radical of the benzene series containing 6 to 10 carbon atoms.

2. An aryl alkylphosphonothioate of the formula IS N02 i wherein R is an alkyl radical containing 1 to 2 carbon atoms and wherein R is an aromatic hydrocarbon radical of the benzene series containing 6 to 7 carbon atoms.

3. An O-(4-nitrophenyl) alkylphosphonothioate of the entrance S NO:

wherein n is an integer from to 1, wherein R is a lower alkyl radical, and wherein R is an aromatic hydrocarbon radical of the benzene series containing 6 to 10 carbon atoms.

9. An insecticidal composition comprising a phosphonothioate dispersed in an extending agent selected from the group consisting of solid and semi-solid extending agents, the composition containing 0.1 to 25 percent by weight of said phosphonothioate, the said phosphonothioate being an aryl alkylphosphonothioate of the formula awe wherein n is an integer from 0 to 1, wherein R is a lower alkyl radical, and wherein R is an aromatic hydrocarbon radical of the benzene series containing 6 to 10 carbon atoms.

10. An insecticidal composition comprising a phosphonothioate dispersed in a liquid extending agent, the composition containing 0.001 to 50 percent by Weight of said phosphonothioate, the said phosphonothioate being an aryl alkylphosphonothioate of the formula a. NO; '-0-1 -o R wherein n is an integer from 0 to Lwherein R is a lower alkyl radical, and wherein R is an aromatic hydrocarbon radical of the benzene series containing 6 to 10 carbon atoms.

11. An insecticidal concentrate comprising a phosphonothioate and an insecticidal adjuvant, said concentrate containing from to 95 percent by weight of the phosphonothioate, the said phosphonothioate being an aryl alkylphosphonothioate of the formula ll R -o 1 e-o- 5 wherein n is an integer from 0 to 1, wherein R is a lower alkyl radical, and wherein R is an aromatic hydrocarbon radical of the benzene series containing 6 to 10 carbon atoms.

12. An insecticidal concentrate comprising a phosphonothioate dispersed in an organic solvent therefor and having dissolved therein a minor amount of a surfactant, said concentrate forming an emulsion with water upon agitation therewith, said phosphonothioate being an aryl alkylphosphonothioate of the formula IS N02 wherein n is an integer from 0 to 1, wherein R is a lower alkyl radical, and wherein R is an aromatic hydrocarbon radical of the benzene series containing 6 to 10 carbon atoms.

13. An insectidical concentrate adapted to be made into a sprayable composition by the addition of water comprising a phosphonothioate in admixture with a watersoluble surfactant in the weight proportion of 0.1 to 15 parts of surfactant and suflicient ofi said phosphonothioate to make parts by weight, said phosphonothioate being an aryl alkylphosphonothioate of the formula mH wherein n is an integer from 0 to 1, wherein R is a lower alkyl radical, and wherein R is an aromatic hydrocarbon radical of the benzene series containing 6 to 10 carbon atoms.

14. The method of controlling insects which comprises contacting the insects with a toxic amount of a phosphonothioate of the formula wherein n is an integer from 0 to 1, wherein R is a lower alkyl radical, and wherein R is an aromatic hydrocarbon radical of the benzene series containing 6 to 10 carbon atoms.

15. The method for protection of plants against insect attack which comprises applying to the plant an insecticidal amount of a phosphonothioate of the formula wherein n, is an integer firorn 0 to 1, wherein R is a lower alkyl radical, and wherein R is an aromatic hydrocarbon radical of the benzene series containing 6 to 10 carbon atoms.

16. The method of controlling insects which comprises contacting the insects with a toxic amount of a phosphonothioate of the formula wherein R is an alkyl radical containing 1 to 2 carbon atoms and wherein R is selected from the group consisting of phenyl, o-tolyl and m-tolyl.

17. The method of protection of plants against insect attack which comprises applying to the plant an insecticidal amount of a phosphonothioate of the formula wherein R is an alkyl radical containing 1 to 2 carbon atoms and wherein R is selected from the group consisting of phenyl, o-tolyl and m-tolyl.

18. The method of controlling insects which comprises contacting the insects with a toxic amount of O-phenyl O-(4-nitrophenyl) methylphosphonothioate.

19. The method for protection of plants against insect said surfactant and sufficient of said methylphosphonothioate to make 100 parts by weight.

References Cited in the file of this patent UNITED STATES PATENTS Fletcher Aug. 29, 1950 Fairchild Oct. 27, 1959 Dunn et a1 Jan. 10, 1961 

1. AN ARYL ALKYLPHOSPHONOTHIOATE OF THE FORMULA 